A large number of orders are processed in a normal work day in a modern photographic processing plant. To expedite the processing, orders containing film of a similar type and size are spliced together for developing. After developing, the film images are printed in an edge-to-edge relationship on a continuous strip of photo sensitive paper by a printer apparatus. The printer apparatus places indicia in the margin to indicate the cutting line between adjacent prints and a seond mark in the opposite margin to indicate the end of an order. The cutter apparatus senses the cutting indicia and separates individual prints from the strip. The separated prints are passed to an order packaging device which groups the prints in response to the end of order marks sensed by the cutter. Thus it may be seen that in a system of this type it is important to positively identify the cutting line between finished prints to provide a means to control an automatic print cutter apparatus.
To be a viable apparatus, the cutter must accommodate the numerous differences that are encountered when dealing with the work product of various photo printers in photographic processing plants. Among these differences is the cutting and end of order indicia configuration. These indicia may vary from a rectangle of approximately 0.030 .times. 0.093 inches to a circle of approximately 0.050 inch diameter depending on the manufacturer of the photo printer. Another variable frequently encountered is the placement of the control indicia from print to print. Experience has shown that deviation in indicia placement may be as large as 0.125 inch laterally from the sensing path center line. The indicia is usually in the form of punched holes or marks on the edge of the strip of prints. The sensing means of previous cutters has demonstrated a high sensitivity to both indicia placement and configuration due to a relatively narrow scanning angle afforded by a photosensitive transistor employed as the sensing element.
Another shortcoming of prior indicia sensors is that the sensor was attached to the cutter device photographic strip guide means. Thus, as adjustments were made in guide positioning to accommodate variations in the width of the photographic strip, the sensor position was likewise effected. The necessary realignment of the sensor was then accomplished by a trial and error procedure in which a highly experienced operator would loosen the sensor mounting screws and realign the sensor to pick up the indicia on the strip.
In the past phototransistors have been used as sensing elements. These elements have a very restricted scanning area which was thought to be an advantage because there would be less chance of a false indicia being sensed. However with the high speed equipment now in use this restricted sensing area has produced the problems outlined above.
The concept of using a wide angle sensing element provides an extremely simple solution to these problems and furthermore the discovery that a photovoltaic or solar cell as the sensing element produces the desired wide angle sensing area and provides the means for implementing this concept. In addition to the wide angle sensing capability of the photovoltaic cell the characteristic of such a cell is to provide a straight line or logarithmic energy producing ratio which is directly proportional to the area on which the radiation source is imposed. This is not true with the phototransistor sensors previously used with such equipment. Solar cell elements are normally used for the conversion of infrared energy to electrical current. However, in the application herein described this element is employed as a wide angle sensor of infrared energy and provides a substantial increase in sensing area and the width thereof when compared to the phototransistor of prior applications.
The invention also provides separation of the sensor mounting means from the photographic strip guide means. Thus, with different film sizes variations in the width of the photographic strip are encountered and the guide means may be repositioned accordingly without affecting placement of the sensor means. This invention also provides for micrometer type adjustments of the sensor means in planes both parallel and normal to the photographic strip for adjusting the sensor position for the various film sizes. These adjustments expedite the cutter set-up procedure. These enhancements are designed for retrofit into existing Pako Model 255 and 255B cutters.